Investigation of Discrepant ABO Blood Grouping Results from an Autoanalyzer

Abstract

Background A paucity of studies evaluating failed cases of ABO grouping using autoanalyzers exists. We investigated autoanalyzer rejected cases, including serologically suspicious ABO subgroups and discrepant ABO blood grouping results from Erytra Eflexis (Grifols, Spain), to demonstrate efficient use of autoanalyzers for ABO grouping. Methods Samples requested for ABO grouping throughout 2020 were tested using two Eflexis instruments and standard ABO RhD and reverse grouping cards. Neonatal cards were not used. When necessary, a conventional tube technique (TUBE) was used to resolve rejected/discrepant Eflexis ABO grouping results. Results The overall sample rejection rate (RR) was 3.2% (628/19,466), 1.3% of which were due to various error flags and 1.9% for discrepant results. Cases from neonates ≤1 year old accounted for 35.3% of the rejected cases based on Eflexis results. The ABO groups with the highest and lowest RR (excluding neonates) were A and O, respectively. The 628 samples resulted in 682 rejections, which were frequently associated with reverse grouping, including 28.4% against A 1 and 54.5% for B red cells. Among 14 serologically weakened A and/or B blood groups, six A 2 BW and two ABw, which had been missed by Eflexis, were detected using TUBE and our follow-up laboratory criteria. Conclusions The ABO group and a proportion of neonatal samples influenced the RR due to weak reverse grouping reactivity, especially toward B red cells. Confirmatory ABO grouping by TUBE in a new patient and/or extra rejection criteria for forward grouping are needed to detect cis -AB, which is relatively common in Korea.

Comparison of Column Agglutination Technique and Tube Test for ABO Antibody Titration and Crossmatching

“…Erytra Eflexis (Grifols, Barcelona, Spain)는 전용 시약과 카 드를 사용하여 원주응집법(column agglutination test, CAT)을 원리로 하여 혈액형 검사를 포함한 각종 면역혈액학적 검사가 가능한 장비이다. 아주대병 원은 2020년 1월 말에 이 장비를 도입하여 국내 대 학병원으로서는 처음으로 사용하고 있다 [1]. 이 장 비는 혈액형 검사, 비예기항체 선별 및 동정검사 및 교차시험용으로 통상적으로 이용되고 있다 [2,3].…”

Allelic Enhancement of BEL.02 With the Single Nucleotide Variant, c.669G>T

“…However, as described above, identical alleles can express various phenotypes according to their counterpart alleles. Several reports [ 10 , 11 ] claimed that various expressions of cis -AB can lead to misclassification in the ABO grouping. Indeed, we were confused by the unexpected phenotype of the proband carrying the BEL.02 allele because of the stronger expression of the B antigen than expected for the B el phenotype.…”